Comparative pathogenicity of goose parvovirus across different epidemic lineages in ducklings and goslings

The endemic status of goose parvovirus (GPV) continues to devastate the poultry industry in China. Novel GPV (NGPV) and Mutated GPV (MGPV) represent the predominant lineages. However, the comparative pathogenicity between these viruses remains poorly understood. Herein, we selected representative NGPV and MGPV strains as model viruses to assess their pathogenic potential both <i>in vitro</i> and <i>in vivo</i>. <i>In vitro</i> cellular and embryo assays demonstrated that both NGPV and MGPV were capable of replicating in DEF and GEF cells, leading to pronounced cytopathic effects. However, these viruses exhibited distinct levels of intra-embryonic replication capabilities. Furthermore, we conducted <i>in vivo</i> infection experiments and systematically evaluated the pathogenic differences between NGPV and MGPV by examining various indicators, including growth, clinical signs, gross pathology, skeletal development, viral load, and humoral response in the infected animals. The results showed that both NGPV and MGPV inhibited weight gain in goslings and ducklings, with NGPV exerting a more significant suppressive impact. MGPV induced classical gosling plague pathology in goslings, while NGPV led to short beak and dwarfism syndrome in ducklings, notably disrupting skeletal development. Moreover, MGPV and NGPV exhibited diverse host tropisms, with MGPV being more pathogenic to goslings and NGPV to ducklings. Both viruses elicited specific antibody responses, with MGPV being more effective in goslings and NGPV in ducklings. Additionally, MGPV exhibited stronger humoral response compared to NGPV. These findings enhance our understanding of the pathogenicity of prevalent GPV strains in waterfowl, offering a critical theoretical foundation for devising strategies to prevent GPV infections.